Because that product seems kind of sketch, chem-based and systemic(gets inside plant).
Meds are often for sick people. Sick people are often sick because of slight differences in their physiology causing them to react poorly to shit that other healthy people just shake off.
Like leftover Ridomil in the weed. Maybe it will push something in my body past a tipping point and give me a debilitating condition, due to my stupid physiology.
You must ask yourself at every turn, if someone I loved very much was doing very poorly, like if you had a child with leukemia, or a wife that was trying hard to not die, would I give them medicine with this stuff in it? It probably is not worth the chance.
The last time I saw this product mentioned it was from a large-scale Canadian grower using Krusty buckets and vert lighting who did not want to run a chiller, so ran water temps like high 70s or 80 or something. Hence the usage of ridomil. But I am guessing that person was exporting bulk amounts, perhaps without considering ethical boundaries.
We should consider using that stuff only if we can establish that it is safe for sick loved ones. Got to make decisions that we can tell our children about proudly when they are adults.